“[9.08] DIAMOND CITY MARKET:  Chem-I-Care: This is a popular establishment, thanks to the genial owner, Solomon. Selling a complete variety of chems and healing supplies, Solomon may have convinced the populace that the benefits of his wares outweigh the risks. Pick the lock of his house (Novice) for a few more chems to steal inside.”— Fallout 4 Vault Dweller's Survival Guide/Map p. 433
This building has an entrance door to Solomon's house to the left of his small covered shop stall. The house consists of a single room, and is extremely messy and filled with garbage, with some consumables, a first aid box, a suitcase, and an owned sleeping bag.
Solomon's house key is needed to enter Solomon's house without lockpicking the Novice-locked door.